Knife sharpener

ABSTRACT

An electric sharpener includes a body having a reception area for receiving a driving device, and a sharpening area in which a gear set is located which is connected with the driving device. A shaft is located in the sharpening area and connected to the gear set. A rough sharpening set connected to the shaft and has a first spring unit. A fine sharpening set is connected to the shaft and has a second spring unit. The first and second spring sets have different spring forces applied to the rough sharpening set and the fine sharpening set.

FIELD OF THE INVENTION

The present invention relates to an electric sharpener, and moreparticularly, to an electric sharpener having two sets of girding diskswith different spring units.

BACKGROUND OF THE INVENTION

A conventional electric sharpener is used to sharpen knives or scissorsand generally includes a grinding wheel which is driven by a motor andthe users press the blade of the knife on the rotating grinding wheel tosharpen it. Some of the conventional sharpeners have two grinding wheelsfor different purposes of sharpening, such as rough sharpening and finesharpening. The two sharpening wheels are connected to the same shaft sothat they are rotated at the same speed, however, the requirements forthe two different types of sharpening are not the same. The usual way isto reduce the speed of the motor to have a compromise. If the speed isadjusted to a high speed, the users have to have certain skill otherwisethe knife may be damaged. The electric power only provides the rotationof the grinding wheels and cannot adjust the pressure that the blade ispressed on the grinding wheels. This restricts the result of sharpeningbecause most of the users do not have the skill to properly operate theknife relative to the grinding wheels.

The present invention intends to provide an electric sharpener whichincludes two spring units for the rough sharpening set and the finesharpening set respectively so as to meet different requirements of thetwo different sharpening actions.

SUMMARY OF THE INVENTION

The present invention relates to an electric sharpener which comprises abody having a reception area and a sharpening area, wherein a drivingdevice is located in the reception area and connected to a gear setlocated in the sharpening area. A shaft is located in the sharpeningarea and connected to the gear set. A rough sharpening set is connectedto the shaft and located beside the gear set. The rough sharpening sethas a first spring unit. A fine sharpening set is connected to the shaftand located beside the rough sharpening set. The fine sharpening set hasa second spring unit. The first and second spring sets apply differentspring forces to the rough sharpening set and the fine sharpening set soas to achieve different purposes of sharpening.

A first fixing ring is located between the first left grinding disk andthe first right grinding disk, and a second fixing ring is locatedbetween the second left grinding disk and the second right grindingdisk. By the two fixing rings, the knife can be precisely inserted intothe two sharpening units and are sharpened steadily.

The primary object of the present invention is to provide an electricsharpener which includes two sharpening units which are cooperated withdifferent spring units so as to provide proper spring forces to the twosharpening units.

Another object of the present invention is to provide an electricsharpener wherein the two spring units have different elasticitycoefficients so that the axial pressures to the two sharpening units aredifferent.

Yet another object of the present invention is to provide an electricsharpener wherein each of the two sharpening units has a positioningring which position the two sharpening units firmly on the shaft so thatthe sharpening action is operated in a stable status.

The present invention will become more obvious from the followingdescription when taken in connection with the accompanying drawingswhich show, for purposes of illustration only, a preferred embodiment inaccordance with the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the front view of the electric sharpener of the presentinvention;

FIG. 2 shows the driving device, the gear set, the shaft and the twosharpening sets of the electric sharpener of the present invention;

FIG. 3 shows the driving device, the gear set, the shaft and the detailstructure of two sharpening sets of the electric sharpener of thepresent invention;

FIG. 4 shows that a knife is sharpened by the rough sharpening set ofthe electric sharpener of the present invention, and

FIG. 5 shows that a knife is sharpened by the fine sharpening set of theelectric sharpener of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 1 to 3, the electric sharpener 10 of the presentinvention comprises a body 10 which includes a reception area 11 and asharpening area 12 which is located beside the reception area 11. Adriving device 20 is located in the reception area 11 and includes anoutput shaft which is connected with a first gear of a gear set 30located in the sharpening area 12. A second gear is engaged with thefirst gear and connected to a shaft 40 which is located in thesharpening area 12. A rough sharpening set 50 is connected to the shaft40 and located beside the gear set 30. The rough sharpening set 50 has afirst spring unit 51. A fine sharpening set 60 is connected to the shaft40 and located beside the rough sharpening set 50. In other words, therough sharpening set 50 is located between the fine sharpening set 60and the gear set 30. The fine sharpening set 60 has a second spring unit61. The first and second spring sets 51, 61 have different spring forcesapplied to the sharpening set 50 and the fine sharpening set 60.

The sharpening area 12 comprises a first slot 121 and a second slot 122,the rough sharpening set 50 is located beneath the first slot 121 andthe fine sharpening set 60 is located beneath the second slot 122. Eachof the first and second slots 121, 122 communicates with a groove 123.

The first spring unit 51 comprises a first left spring 511 and a firstright spring 512, and the rough sharpening set 50 comprises a firstsharpening unit 52 which is located between the first left spring 511and the first right spring 512. The first sharpening unit 52 comprises afirst left grinding disk 521 and a first right grinding disk 522. Thefirst left grinding disk 521 contacts the first left spring 511 and thefirst right grinding disk 522 contacts the first right spring 512. Afirst fixing ring 523 is located between the first left grinding disk521 and the first right grinding disk 522. A first positioning plate 524is located in the first right grinding disk 522 and the first rightspring 512 contacts the first positioning plate 524. The first leftgrinding disk 521 and the first right grinding disk 522 are two circularplates. The first right grinding disk 522 is inserted into a recessedarea of the first left grinding disk 521.

The second spring unit 61 comprises a second left spring 611 and asecond right spring 612. The fine sharpening set 60 comprises a secondsharpening unit 62 which is located between the second left spring 611and the second right spring 612. The second sharpening unit 62 comprisesa second left grinding disk 621 and a second right grinding disk 622.The second left grinding disk 621 contacts the second left spring 611and the second right grinding disk 622 contacts the second right spring612. A second fixing ring 623 is located between the second leftgrinding disk 621 and the second right grinding disk 622. A secondpositioning plate 624 is located in the second right grinding disk 622and the second right spring 612 contacts the second positioning plate624. The second left grinding disk 621 and the second right grindingdisk 622 are two circular plates. The second right grinding disk 622 isinserted into a recessed area of the second left grinding disk 621.

The shaft 40 has a first flange 70, a second flange 80 and a thirdflange 90 mounted thereto, wherein the first flange 70 is located and incontact between the first spring unit 51 and the second spring unit 61.The second flange 80 is located such that the first spring unit 51contacts the second flange 80 and the third flange 90 is located suchthat the second spring unit 61 contacts the third flange 90. The firstspring unit 51 and the second spring unit 61 have different elasticitycoefficients so as to provide different forces to the rough and finesharpening sets 50, 60 to meet different types of sharpeningrequirements.

Referring to FIGS. 4 and 5, when sharpening a knife “K”, the blade “K1”of knife “K” is first inserted into the first slot 121 of the roughsharpening set 50, the first slot 121 guides the blade “K1” and twosides of the blade “K1” are in contact with the first left grinding disk521 and the first right grinding disk 522. The driving device 20 drivesthe gear set 30 and the shaft 40, the first sharpening unit 52 isrotated with the shaft 40 so that the first left grinding disk 521 andthe first right grinding disk 522 sharpen the blade “K1”. The userpresses the knife “K” to let the first left grinding disk 521 and thefirst right grinding disk 522 sharpen the blade “K1” continuously.Because the first spring unit 51 has larger spring force, so that therough sharpening set 50 provide intensive sharpening feature to theblade “K1”. The blade “K1” enters into the groove 123 of the first slot121 and cannot be inserted further so as to avoid the blade “K1” frombeing in contact with the shaft 40 and damaged.

After the rough sharpening is completed, the knife “K” has surplusmaterial on the sharpened area and is then sharpened in the finesharpening set 60. The blade “K1” of knife “K” is inserted into thesecond slot 122 and two sides of the blade “K1” are in contact with thesecond left grinding disk 621 and the second right grinding disk 622.The driving device 20 drives the gear set 30 and the shaft 40, thesecond sharpening unit 62 is rotated with the shaft 40 so that thesecond left grinding disk 621 and the second right grinding disk 622further sharpen the blade “K1”. Again, the user presses the knife “K” tolet the second left grinding disk 621 and the second right grinding disk622 sharpen the blade “K1” continuously. Because the second spring unit61 has smaller spring force than the first spring unit 51, so that thefine sharpening set 60 provides fine sharpening feature to the blade“K1”. The blade “K1” enters into the groove 123 of the second slot 122and cannot be inserted further so as to avoid the blade “K1” from beingin contact with the shaft 40 and damaged.

Because the first and second spring units 51, 61 have different springforces so that the rough and fine sharpening sets 50, 60 have differentaxial pressure to sharpen the knife “K” to obtain different sharpeningresults.

The first and second fixing rings 523, 623 ensure that the rough andfine sharpening sets 50, 60 are properly installed on the shaft 40 sothat the knife “K” can be sharpened in a stable status.

While we have shown and described the embodiment in accordance with thepresent invention, it should be clear to those skilled in the art thatfurther embodiments may be made without departing from the scope of thepresent invention.

1. An electric sharpener comprising: a body having a reception area anda sharpening area; a driving device located in the reception area; agear set located in the sharpening area and close to the reception area,the gear set connected with the driving device; a shaft located in thesharpening area and connected to the gear set; a rough sharpening setconnected to the shaft and located beside the gear set, the roughsharpening set having a first spring unit and a first sharpening unit,the first spring unit comprising a first left spring and a first rightspring, the first sharpening unit located between the first left springand the first right spring, the first sharpening unit comprising a firstleft grinding disk and a first right grinding disk, the first leftgrinding disk contacting the first left spring and the first rightgrinding disk contacting the first right spring, a first fixing ringlocated between the first left grinding disk and the first rightgrinding disk, a first positioning plate located in the first rightgrinding disk and the first right spring contacting the firstpositioning plate, the first left grinding disk and the first rightgrinding disk being two circular plates, the first right grinding diskbeing inserted into a recessed area of the first left grinding disk; afine sharpening set connected to the shaft and located beside the roughsharpening set, the fine sharpening set having a second spring unit anda second sharpening unit, the second spring unit comprising a secondleft spring and a second right spring, the second sharpening unitlocated between the second left spring and the second right spring, thesecond sharpening unit comprising a second left grinding disk and asecond right grinding disk, the second left grinding disk contacting thesecond left spring and the second right grinding disk contacting thesecond right spring, a second fixing ring located between the secondleft grinding disk and the second right grinding disk, a secondpositioning plate located in the second right grinding disk and thesecond right spring contacting the second positioning plate, the secondleft grinding disk and the second right grinding disk being two circularplates, the second right grinding disk being inserted into a recessedarea of the second left grinding disk, the first and second spring setshaving different spring forces, and the shaft having a first flange, asecond flange and a third flange mounted thereto, the first flangelocated and in contact between the first spring unit and the secondspring unit, the second flange located such that the first spring unitcontacts the second flange, the third flange located such that thesecond spring unit contacts the third flange.
 2. The sharpener asclaimed in claim 1, wherein the sharpening area comprises a first slotand a second slot, the rough sharpening set is located beneath the firstslot and the fine sharpening set is located beneath the second slot. 3.The sharpener as claimed in claim 2, wherein each of the first andsecond slots communicates with a groove.